A lidar system having a light source to emit an output beam and an overlap mirror having a reflecting surface with an aperture through which the output beam passes. The lidar system may include mirrors driven by a galvanometer scanner, a resonant scanner, a microelectromechanical systems device, or a voice coil motor. The mirrors may direct the output beam toward a light source field of view (FOV) and may move the light source FOV to different locations within a field of regard. The mirrors may receive reflected portions of the output beam as an input beam and direct the input beam toward the reflecting surface of the overlap mirror. The lidar system may include a receiver to receive the input beam from the reflecting surface of the overlap mirror. The receiver may have a receiver FOV that moves synchronously with, and at least partially overlaps, the light source FOV.
1. A lidar system comprising:
a light source configured to emit pulses of light as an output beam;
an overlap mirror comprising a reflecting surface with an aperture through which the output beam passes;
a scanner comprising one or more mirrors driven by a galvanometer scanner, a resonant scanner, a microelectromechanical systems (MEMS) device, or a voice coil motor, the one or more mirrors being configured to direct the output beam toward a light source field of view within a field of regard and to move the light source field of view to different locations within the field of regard, the one or more mirrors being further configured to receive reflected or scattered portions of the output beam as an input beam and to direct the input beam toward the reflecting surface of the overlap mirror; and
a receiver configured to receive the input beam from the reflecting surface of the overlap mirror, the receiver having a receiver field of view that moves synchronously with, and at least partially overlaps, the light source field of view, wherein
the light source field of view and the receiver field of view are scanned along a scanning direction; and
the receiver field of view is offset from the light source field of view in a direction opposite the scanning direction.
2. The lidar system of claim 1 , further comprising a sensor head located remotely from the light source, wherein:
the sensor head comprises the scanner and the receiver; and
the sensor head is coupled to the light source by an optical link.
3. The lidar system of claim 2 , wherein:
the lidar system further comprises one or more additional sensor heads;
each of the additional sensor heads comprises a respective scanner and receiver; and
the light source is coupled to each of the additional sensor heads by a respective optical link.
4. The lidar system of claim 3 , wherein the lidar system is incorporated into a vehicle, and wherein the sensor head and the one or more additional sensor heads of the lidar system are positioned about the vehicle to provide at least a 180-degree view of an environment around the vehicle.
5. The lidar system of claim 1 , wherein the lidar system has a maximum range of at least 50 meters.
6. The lidar system of claim 1 , wherein the field of regard comprises:
a horizontal field of regard of at least 25 degrees; and
a vertical field of regard of at least 5 degrees.
7. The lidar system of claim 1 , wherein the lidar system has a horizontal resolution of at least 100 pixels and a vertical resolution of at least 4 pixels.
8. The lidar system of claim 1 , wherein the lidar system is configured to generate point clouds of distance measurements at a rate between approximately 0.1 frames per second and approximately 1,000 frames per second.
9. The lidar system of claim 1 , wherein the scanner comprises:
a first mirror driven by a first galvanometer scanner that scans the first mirror along a first direction; and
a second mirror driven by a second galvanometer scanner that scans the second mirror along a second direction substantially orthogonal to the first direction.
10. The lidar system of claim 1 , wherein the scanner comprises:
a first mirror driven by a resonant scanner that scans the first mirror along a first direction; and
a second mirror driven by a galvanometer scanner that scans the second mirror along a second direction substantially orthogonal to the first direction.
11. The lidar system of claim 1 , wherein the scanner comprises two mirrors driven synchronously, wherein the synchronously driven mirrors trace out a scan pattern that comprises substantially straight lines.
12. The lidar system of claim 1 , wherein the scanner comprises a mirror driven by two actuators configured to scan the mirror along two substantially orthogonal directions.
13. The lidar system of claim 1 , wherein the scanner comprises a mirror configured to be scanned along two axes, wherein motion along each axis is provided by two actuators arranged in a push-pull configuration.
14. The lidar system of claim 1 , wherein an angular extent of the light source field of view is approximately equal to an angular extent of the receiver field of view.
15. The lidar system of claim 1 , wherein:
the light-source field of view has an angular extent of less than or equal to 50 milliradians; and
the receiver field of view has an angular extent of less than or equal to 50 milliradians.
16. The lidar system of claim 1 , wherein an angular extent of the receiver field of view is approximately twice an angular extent of the light source field of view.